Must Articles 2(1)(c), 64(1), 66(a) and 73 of Directive 2006/112/EC be interpreted as meaning that a telecommunications operator (television, internet, mobile network and fixed network) is liable for value added tax as a result of charging its customers –– in a case of termination, for reasons attributable to the customer, of a contract containing an obligation to be bound by the contract for a defined term (tie-in period) before the end of that period –– a pre-determined amount, corresponding to the basic monthly amount payable by the customer under the contract, multiplied by the number of monthly payments that are still to be made before the end of the tie-in period, the operator having, at the time when that amount is invoiced and independently of its actual payment, already ceased to provide the services.